Cherie Blair is a thoroughly modern mother. Since moving into Downing Street three years ago, the prime minister's wife has juggled her duties of bringing up three children, working as a top flight barrister and accompanying her husband on state business.

Even her fourth pregnancy, at the age of 45, did not noticeably slow her down. She worked to the wire, appearing in court recently for the TUC, in a case against the government.

Now the pressure cooker atmosphere in Number 11, where the Blairs inhabit an upstairs apartment, is certain to increase a notch or two with the arrival of the new baby.

Hats off to Cherie as she shows off her bump

Since word first broke about the imminent arrival, in November last year, Mrs Blair has been the focus of intense media interest.

Will she return to work? When will she return to work? Did she insist Tony took parental leave? Will her mother move in to help? Will she opt for old-fashioned terry nappies, disposables or even "eco-nappies".

The press pounced on an embarrassing episode in January, when she was find for fare dodging after jumping on a train to Luton, where she was due to sit as a magistrate.

In the face of such attention, Mrs Blair has maintained her composure and let hardly a word slip into the public domain.

Tony Booth, left, walked out on Cherie when she was a toddler

Her plans for the future are unknown. Although she has cut back her work as a lawyer since moving to Downing Street, she is still thought to contribute more than £100,000 a year to the family coffers.

Mrs Blair, who works under maiden name Cherie Booth, is a specialist in employment law and currently sits as a part-time judge, or recorder. It is said she could be made a full judge within three years.

Recently she was involved in setting up new chambers designed to handle human rights issues in court.

And although she has, at times, seemed uncomfortable with the unofficial mantle of Britain's "first lady", she has taken on a public role.

She holds regular Downing Street tea parties for constituency children and offers her support to several charities, notably Breast Cancer Care, and good causes. Mrs Blair receives about 250 letters a week.

Tickets please: Cherie shows her travel credentials

Mrs Blair does not give interviews but once listed "keeping fit and enjoying my children" as among her recreations.

Born in 1954, Cherie Booth was brought up in a working class, Roman Catholic family in Bury, Lancashire. Her father, the actor Tony Booth, who later became famous for his role in the BBC comedy Til Death Us Do Part, walked out when she was two.

A hard-working and conscientious student, she earned a first in her law degree at the London School of Economics and came top of her year in the bar exams.

Cherie met Tony while they were both training to be barristers.

She was an active supporter of the Labour Party and it has been said Tony stepped up his involvement with the party to impress her.

The Blairs have been closely compared to the Clintons

They married in 1980.

Mrs Blair fought and lost the no-hope seat of Thanet North in Kent at the 1983 general election. In the same year her husband won his safe seat in Sedgefield, County Durham, and began the long climb to government.

The Blairs have frequently been compared to the Clintons but, while Hillary is stepping up her own political career by bidding to become a senator, Cherie may choose to put her legal career on the back burner to raise her fourth child.